add flake.nix

Co-authored-by: Tobias Happ <Gerschtli@users.noreply.github.com>

.gitignore

@@ -1,3 +1,4 @@
 result
 result-*
 out
+flake.lock

CHANGELOG.md

@@ -15,6 +15,10 @@ if the `system.stateVersion` option is set to `"20.09"` or later.
   either or attempt an upgrade to `release-19.09`
   and follow the instructions, or backup and reinstall (preferred).
 
+## Nix flakes support
+
+* A `flake.nix` file was added.
+
 ## Known issues:
 
 * If `make` fails on your device with `Function not implemented`,

README.md

@@ -157,7 +157,23 @@ if you are planning to maintain a long-term fork that users can update from.
 In case you only care about updates through wiping the data,
 you shouldn't need a binary cache for that.
 
+## Nix flakes
 
+Example, to use with nix flakes:
+
+```nix
+{
+  description = "nix-on-droid configuration";
+
+  inputs.nix-on-droid.url = "/home/bbigras/src/nix-on-droid";
+
+  outputs = { nix-on-droid, ... }: {
+    nix-on-droid = (nix-on-droid.lib.aarch64-linux.nix-on-droid { config = ./your_config.nix; } ).activationPackage;
+  };
+}
+```
+
+Build with `nix build .#nix-on-droid --impure`.
 
 ## Tips
 

flake.nix

@@ -0,0 +1,36 @@
+{
+  description = "Nix-enabled environment for your Android device";
+
+  inputs = {
+    flake-utils.url = "github:numtide/flake-utils";
+    home-manager = {
+      url = "github:nix-community/home-manager";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+  };
+
+  outputs = { self, nixpkgs, home-manager, flake-utils }:
+    flake-utils.lib.eachSystem [
+      "aarch64-linux"
+      "i686-linux"
+    ]
+      (system:
+        let pkgs = nixpkgs.legacyPackages.${system}; in
+        rec {
+          lib = {
+            nix-on-droid = { config }: import ./modules {
+              inherit pkgs config;
+              isFlake = true;
+              home-manager = (import home-manager { });
+            };
+          };
+
+          overlays = ./overlays;
+
+          apps.nix-on-droid = flake-utils.lib.mkApp {
+            drv = (pkgs.callPackage ./nix-on-droid { });
+          };
+          defaultApp = apps.nix-on-droid;
+        }
+      );
+}

modules/default.nix

@@ -1,6 +1,6 @@
 # Copyright (c) 2019-2020, see AUTHORS. Licensed under MIT License, see LICENSE.
 
-{ pkgs ? import <nixpkgs> { }, home-manager ? import <home-manager> { }, config ? null }:
+{ pkgs ? import <nixpkgs> { }, home-manager ? import <home-manager> { }, config ? null, isFlake ? false }:
 
 with pkgs.lib;
 
@@ -20,7 +20,7 @@ let
         _module.args.pkgs = mkDefault pkgs;
       }
       configModule
-    ] ++ import ./module-list.nix { inherit pkgs; };
+    ] ++ import ./module-list.nix { inherit pkgs isFlake; };
   };
 
   failedAssertions = map (x: x.message) (filter (x: !x.assertion) rawModule.config.assertions);

modules/module-list.nix

@@ -1,6 +1,6 @@
 # Copyright (c) 2019-2020, see AUTHORS. Licensed under MIT License, see LICENSE.
 
-{ pkgs }:
+{ pkgs, isFlake }:
 
 [
   ./build/activation.nix
@@ -12,10 +12,9 @@
   ./environment/path.nix
   ./environment/session-init.nix
   ./home-manager.nix
-  ./nixpkgs.nix
   ./time.nix
   ./user.nix
   ./version.nix
   ./workaround-make.nix
   (pkgs.path + "/nixos/modules/misc/assertions.nix")
-]
+] ++ pkgs.lib.optionals (!isFlake) [ ./nixpkgs.nix ]